The invention relates to methods of marking products, and to products produced by such methods in a coded, retrievable and relatively non-destructible manner such that a respective product can be later identified and its history tracked despite transformations that may have occurred, short of the complete destruction of the product. The invention also relates to applications of such methods, and to products produced by such methods.
Various techniques have been used for marking or tagging products in order to enable tracking a product or determining the source of a product under examination. For example, tagging ingredients have been added to chemical compositions, and radio-frequency identifications (RFID) labels have been applied to product containers. However, in the known techniques, the tag is usually destroyed with the transformation or conversion of the product into another form, thereby precluding the identification of the source of the product. Moreover, the tagging ingredients usually relates only to the source or identity of the respective product, and provide little or no information as to the history of the respective product.